The present invention relates generally to dispatching systems, and more particularly, to a method and system for optimizing assignment of trucks in an open-pit mining environment.
In a number of industries, vehicles or other transportation methods are used to pick up loads from one location and deliver the loads to another location. Some exemplary industries that work within this model include shipping, package delivery, and taxi-cabs. This model has particular application in the mining industry, where material transportation involves a truck picking up a load of ore from a shovel site and transporting that ore to a processing site. Additionally, processed ore may need to be transported to a site of additional processing. Because of this, material transport is one of the most important aspects in the mining industry and can represent 50-60% of costs associated with open-pit mining.
Even a slight reduction in costs associated with material transport may result in significant savings. Thus, a dispatching system for controlling the trucks within a mine can be used to optimize material transport and reduce costs. The essence of a dispatching system is to determine, every time a truck leaves a site in the mine, where is the xe2x80x9cbestxe2x80x9d place for that truck to go. Determining the xe2x80x9cbestxe2x80x9d place involves optimizing one or more objectives, such as minimizing the waiting time of trucks at processing sites, maximizing the overall production of the mine, or minimizing hauling distances.
Two approaches have been used for truck dispatch systemsxe2x80x94single-stage and multi-stage. Single-stage systems dispatch trucks according to one or several criteria. Single-stage systems, however, do not take into account any production targets or constraints. Often single-stage systems use heuristic, or non-mathematical, rules to determine the truck assignments. Multi-stage systems, on the other hand, divide dispatching problems into multiple stages. Typically, multi-stage systems include an upper stage, which consists of setting production targets for each shovel, and a lower stage, which consists of assigning trucks to shovels to minimize deviation from the production targets suggested in the upper stage. Traditionally, regardless of the approach used, truck dispatching systems have been concerned with only one truck and/or one shovel or processing site. Further, truck dispatching systems can often only consider a single goal, such as maximizing production. For example, one such system is disclosed in U.S. Pat. No. 3,979,731, entitled xe2x80x9cMethod of and System for Rationalizing the Operation of Open-Pit Mines.xe2x80x9d This system evaluates the ore to be loaded at each loading station (or shovel) and determines the number of vehicles to be routed to each station. The system takes into account production quotas, number of vehicles waiting, and the travel times associated with each available vehicle. This system, however, is not able to truly optimize material transport because it does not provide adaptable guidelines, nor does it provide for real-time decision making that permits on-the-fly changes in response to unplanned events.
In order to truly optimize material transport, multi-stage systems must be able to, in the upper stage, adapt guidelines based on the current mine environment. For example, when a mine has a shortage of trucks, it is inefficient to minimize truck idle time, because it is unlikely that a truck would be required to wait in the xe2x80x9cunder-truckedxe2x80x9d scenario. Further, these guidelines must adapt to changes such as the break-down of a shovel. The adaptability of guidelines must not only take into account the current state of the mine, but also be able to account for upcoming events that may change the mine environment, such as a number of broken-down shovels becoming operational.
In the lower stage, the system must be able to make real-time dispatching decisions. Further, these dispatch decisions should account for the fact that multiple trucks may cooperate, rather than each truck seeking the best decision only for itself. The lower stage should dispatch a number of trucks to follow the guidelines determined by the upper stage. The lower stage must also have some mechanisms in order to react efficiently to minor, unplanned events, that were not considered by the upper stage.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
A system is provided for providing dispatch assignments. The system includes a plurality of vehicles, a plurality of sources, a plurality of processing sites, and a base computer. The base computer is configured to provide dispatch information to individual vehicles based upon a cooperative assignment of multiple vehicles within the plurality of vehicles.
Further, a method is provided for providing dispatch assignments to a plurality of vehicles in an environment including a plurality of sources and a plurality of processing sites. Current information about the environment is obtained, as is information about optimal criteria. Based on the current environment and the optimal criteria information, a production plan is determined. A plurality of possible dispatch assignments for each vehicle is determined based on the production plan and costs associated with each possible dispatch assignment are determined. Based upon consideration of a cooperative assignment of multiple vehicles within the plurality of vehicles, a dispatch assignment is selected for each vehicle from among the possible dispatch assignments.
A computer readable medium including instructions for performing the above method is also provided.
Further, another system is provided for providing dispatch assignments within an environment. The system includes a plurality of vehicles, a plurality of sources, a plurality of processing sites, and a base computer. The base computer is configured to provide dispatch information to the plurality of vehicles based on anticipated future environment conditions.
Another method is provided for providing dispatch assignments to a plurality of vehicles in an environment including a plurality of sources and a plurality of processing sites. Current and anticipated future information about the environment is obtained, as is information about optimal criteria. Based on the current environment and the optimal criteria information, a production plan is determined. A plurality of possible dispatch assignments for each vehicle is determined based on the production plan and costs associated with each possible dispatch assignment are determined. Based on the production plan and anticipated future environment conditions, a dispatch assignment is selected for each vehicle from among the possible dispatch assignments.
A computer readable medium including instructions for performing the above method is also provided.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.